Folding scaffold with central support



Dec. 6, 1966 C. E. EVANS ETAL FOLDING SCAFFOLD WITH CENTRAL SUPPORT 2Sheets-Shem 1 Filed Dec. 31, 1964 INVENTORS CHAELES EUGENE Elm/vsW/LL/AM ANTHONY/64: 5AM WILL/AM Hmzaw HAWLEYJR ATTOENEY Dec. 6, 1966 c.E. EVANS ETAL 3,

FOLDING SCAFFOLD WITH CENTRAL SUPPORT Filed Dec. 51, 1964 2 Sheets-Sheetf3 INVENTORJ CHAELEE EL/ENE EVANS W/LL/AM ANTHONY mum WILL/AM HmeowHAM/LE7 JR.

United States Patent Office 3,289,788 Patented Dec. 6, 1966 FOLDINGSCAFFOLD WfTI-l CENTRAL SUPPORT Charles Eugene Evans, Charleston,William Anthony Kapella, Dunbar, and William Harold Hawley, .Ir., St.

Albans, W. Va., assignors to Goodrich-Gulf Chemicals,

Inc., Cleveland, ()hio, a corporation of Ohio Filed Dec. 31, 1964, Ser.No. 422,742 17 Claims. (Cl. 182-428) This invention relates toscaffolding and more particularly to centrally supported foldingscaffolding particularly useful inside agitated vessels.

Cleaning and repair of closed vessels or reaction tanks having agitatorsfor stirring the contents therein has long presented a diflicultproblem, especially when, as is commonly the case, such tanks are topopening and access to the interior is only gained through a relativelysmall manhole or trap door. It has been customary to use ladders or toerect and disassemble temporary or makeshift scaffolding within thevessel or tank. Such procedures have proven inefficient, costly and timeconsuming and, even more important, unsafe because of the temporarynature of the structures used, the insecure footings for the ladders andscaffolding caused by the generally rounded bottoms frequently found insuch tanks, and the location and nature of the agitator which furtherinterfered with erection and use of ordinary makeshift scaffolding andladders.

Accordingly, the general object of this invention is the provision of anew and improved centrally supported scaffolding.

Other objects of this invention are the provision of a new and improvedtemporary scaffolding supported on a central shaft, pole or the like andthe provision of such a scaffolding which is easily and quickly erectedand dismantled; which is sturdy, safe and economical in use; and, whichis collapsible and foldable for easy handling and storage whendismantled.

Still other objects of this invention are the provision of a new andimproved centrally supported scaffolding particularly adapted for useinside agitated vessels and the like, which is foldable, collapsible andreusable; which may be made in a wide range of sizes for vessels andagitators of widely varying size, diameter and impeller structure; whichis quickly and easily erected and dismantled; which is rigid and safewhen erected, easily disassembled, folded and collapsed for passage intoor out of the vessel through even small manholes and trap doors; and,which has separable, quickly installed and removed platforms that arepositively held against disengagement through lateral movement.

Still another object of this invention is the provision of a new andimproved centrally supported scaffolding attaining one or more of theobjects set forth above.

These and other objects and advantages of this invention will appearfrom the following description of a preferred form thereof, referencebeing had to the accompanying drawings in which:

FIGURE 1 is a schematic elevation of a centrally supported scaffoldingembodying a preferred form of this invention shown in use in an agitatedvessel, typical of the broad, general type of vessel for whichscaffolding embodying this invention is particularly useful;

FIGURE 2 is a top view of the scaffolding of FIGURE I, viewed along theline 2-2 of FIGURE 1;

FIGURE 3 is an exploded view, on an enlarged scale, with the platformsremoved, of a slightly different preferred form of the scaffolding shownin FIGURE 1;

FIGURE 4 is a top view, on an enlarged scale, of a platform shown inFIGURE 1; and

FIGURE 5 is a broken section, viewed along the lines 5-5 of FIGURE 2,showing the platform interlock of the preferred form of this invention.

Briefly, a scaffold embodying a preferred form of this invention isadapted to be detachably mounted on and supported by a central shaft orpole and to provide a platform, at a predetermined height, for the safeand sturdy support of one or more workmen or" other persons. Thescaffold is quickly and easily mounted on and detached from thesupporting shaft and is collapsible and foldable so that it is easilyhandled and readily passed into and out of relatively small manholes,trap doors and the like to the end that it may be used in reaction tanksand other vessels having small access means. In addition, the scaffoldis constructed so that it is safely supported at spaced apart points onthe pole or shaft, and is, therefore, useful on poles and shafts whichhave agitators, impeller blades or other structures protrudingtherefrom.

More particularly, a scaffold embodying a preferred form of thisinvention is indicated generally at 1 in FIG- URE l and is shown mountedon the agitator shaft 2 of the vessel or tank 4.

Shaft 2 is supported by a foot bearing 5 and is rotated by an externalmotor 7 in a conventional manner. A plurality of vertically spaced,impeller or agitator blades 8 are fixedly mounted on shaft 2 to rotatetherewith.

Access to the interior of vessel 4 is attained by means of a top openingmanhole or trapdoor it) which is otherwise closed, in a conventionalway, by a cover 11.

Manhole It) is of sufiicient size to permit passage of a man into andout of the vessel.

Vessel i, as described above, is old and well known in the art and, perse, is not a part of the instant invention.

As pointed out above, difficulty, inemcient waste of time and money, andundue hazard have attended the task of cleaning vessels and tanks, astypified by vessel 4, because of the problems and hazards incident tothe erection, use and dismantling of makeshift scaffolding and ladderswithin the vessel. Yet the vessels are of such height that they cannotbe cleaned, except the workmen be supported above the bottom of thevessel. And, of course, the bottom itself is, as shown, frequentlycurved and rounded and does not, therefore, offer a firm, safe orconvenient footing for a support structure or scaffold within thevessel.

In contrast, the scaffolding 1, embodying this invention, is supportedwithin the vessel 4 in a rigid and sturdy manner independent of theshape and curvature of the vessel and the bottom thereof and withoutresting or bearing on the vessel, per se.

To this end scaffold 1 is detachably mounted on and supported by acentral pole, such as agitator shaft 2, by collar means which preferablycomprise upper and lower vertically spaced collars 13a and 13b,respectively, (FIG. 3) and which neither interferes with nor isinterfered with by the agitator blades 8 or other vertically spacedprojections mounted on or carried by the support shaft. Collars 13a and1312, as will hereinafter more fully appear, also provide for a strongand rigid support of the scaffold platform without waste of material orunnecessary increase in weight and decrease in maneuverability andhandling case, which would result from a single long collar, albeit,where the central pole has no agitator blades or other projectionsthereon, a single long collar may be used and attainment of otherobjects and advantages of this invention still realized. And,alternatively, collars 13a and 13b may be joined together by suitablemeans, such as angle irons 14, see FIGURE 3, so as to maintain thescaffold as a unitary whole and increase the strength and rigidity.

In order to provide for quick and easy mounting and removal of thecollars 13a and 13b on the supporting 3 shaft, the collars arepreferably split, as best seen in FIGURE 3, and the respective collarhalves are provided with apertures which are aligned, when the collarhalves are assembled, and receive a pin or pintle for holding theassembled collar together and about the support shaft, when thescaffolding is erected and in use.

To this end the split halves of collars 13a and 13b are preferablyprovided with a plurality of coacting gudgeons 16, at their respectiveedges, of the type common to ordinary hinges. Gudgeons 16 are juxtaposedand interlocked, when the collars 13a and 13b are assembled, to receivepin 17 to hold the collars assembled. Also, if desired, the gudgeons 16at the edges of each collar half are complementarily disposed so that atone side they are as shown in collar 13a, at the front in FIGURE .3, andat the other side they are the reverse, as shown in collar 1312, at thefront in FIGURE 3. In such instance, each collar half has two gudgeonsat one meeting line and three at the other and two exactly similarhalves can be used to form a completed collar 13a or 13b.

In order to provide a strong and rigid support for a horizontal platformupon which workmen and others can stand when using the scaffold aplurality of horizontal struts or arms 19 are mounted on the uppercollar 13a and extend radially outwardly therefrom and an equal numberof generally vertical struts 20 are supported in vertically spacedrelation with the struts 19, on lower collar 13b and are connected,respectively, with the outer ends of struts 19. Struts 19 are held in ahorizontal position by bearing upon upper collar 13a and by verticalstruts 20 which also function to transmit at least a portion of the loadon struts 19 to the lower collar 13b and thence to the supporting shaft.

In order to make scaffold 1 collapsible and foldable and in order toprovide for selective placement and vertical spacing of the collarsrelative to each other so that the same may be used with shafts havingagitators and blades at differing locations, when angle irons 14 areomitted from the scaffold, struts 19 and 20 are pivoted together and tothe collars 13a and 13b, respectively, and in addition struts 20 arepreferably of adjustable length or extensible.

To this end collars 13a and 13]) are provided with a plurality ofequiangularly spaced ears or lugs or pairs of ears and lugs 23, and thestruts 19 and 20 are, respectively, pivotally secured thereto bysuitable means such as pins or bolts, not shown. Also, if similar lugs23 are used, for example, on both the upper and lower collars 13a and13b, and are symmetrically spaced relative to the meeting lines or edgesof the collar halves and are vertically aligned, the collar halves willalso be similar in this respect and mutually interchangeable so that, ineffect, a single collar half can be used as any of the four collarhalves shown.

Struts 19 support platforms 24 which provide the surface upon which theuser of the scaffold stands. Platforms 24 must be firmly supported onthe struts 19 and to this end include means preventing lateral movementwhich would permit the platform to slip off the strut and fall. Inaddition, it is desired that the platforms in a single scaffolding be ofsimilar construction and symmetrical so as to be interchangeable andthat the platforms be quickly and easily placed in position and detachedfrom the supporting structure and fold or collapse so as to pass easilyinto and out of the tank or vessel 4.

To these ends, each horizontal arm or strut 19 preferably comprises apair of back to back channel members 30. and 31, see FIGURE 5, which aresecured together and are conveniently of substantially similarstructure. Channel members 30 and 31 may be formed of any convenientmetal or other suitable material, and in any convenient manner, eitherfrom sheet material or by extrusion, and conveniently comprise a base33, sides 34 and reentrant flanges 36 extending inwardly from therespective sides 34 and defining a channel opening, which, in the caseof the upper channel 31, receives and holds the edges of adjacentplatforms 24, as will hereinafter more fully appear.

The inner ends of channels 30 and 31 bear upon the upper collar 13b andso prevent the struts 19 from folding downwardly, as Well astransmitting force and load to the upper collar.

Further, in order to facilitate pivoting struts 19 on lugs 23, channel31 is provided with upstanding cars 37, see FIGURE 3. 7

Vertical struts 20 preferably comprise an outer tubular member 39 and aninner rod 43 slidably disposed within tube 39 and extensible relativethereto so that the scaffold may be folded when the collars are joined,as in FIGURE 3, or the collars may be spaced at different preselecteddistances apart when as in FIGURE 1.

In order to pivotally connect each vertical strut 20 with thecorresponding horizontal strut 19, a transverse tube 42 is convenientlysecured to the upper end of rod 40 and held within channel 30 by a pinor bolt, not shown, which is disposed in apertures 43 formed in channel39 and tube 42.

Members 39 are pivoted on the respective lugs 23 on collar 13b by a pinor bolt, not shown, extending through the lugs and through apertures 44formed in the members 39, respectively.

In addition, in the form of the invention shown in FIG- URE 1, struts 20are adjusted, when necessary, and force transmitted from the rod 40 tothe tube 39 by any desired suitable means such as, a drift pin 46, whichmay be disposed in a preselected one of a plurality of apertures 47along the length of tube 39 and against which rod 44 bears when thescaffold is erected and'in use.

Platforms 24 are made of wood or other convenient material andpreferably comprise two sections 24a and 24b, FIGURE 4, hinged togetherby hinges 50. Platforms 24 are preferably of truncated triangular shapeand they are of such length that their respective edges lie on theadjacent flanges 36 of the channels 31 of adjacent struts 19.

Further, to prevent lateral movement or accidental disengagement of theplatform 24 from the strut 19, as noted above, a flange 52, see FIGURES4 and 5, is secured along each edge of platform 24. Each flange 52 seatswithin the channel opening defined by flanges 36 on a channel member 31.Each platform 24 is further held against lateral movement by cleats 54,or the like, fastened to the underside of platform 24, see FIGURE 5, andspaced from each flange 52 a sufficient distance to provide a seat forthe adjacent flange 36. Thus platforms 24 are securely held againstlateral displacement, yet may be quickly and easily placed upon orremoved from struts 19 during erection or dismantling of the scaffoldand the structural members of the scaffold are themselves easily erectedand dismantled by insertion or removal, as the case may be, of pins 17.The scaffold disassembles and folds compactly for ease in passing itinto and out of the vessel through the manhole 1t) and obviously thelength of struts 19 and dimensions of the platform 24 depend on thediameter of the vessel or vessels within which the scaffolding is to beused.

Modifications, changes and improvements in the preferred embodiments ofthe invention herein depicted and described will occur to those skilledin the art who come to understand the principles and precepts thereof.Accordingly, the patent to be issued herein should not be limited by thespecific disclosures made herein, but only by the advance by which theinvention has promoted the art.

It is intended that the patent shall cover, by summarization in appendedclaims, all features of patentable novelty residing in the invention.

We claim:

1. A folding collapsible scaffolding for mounting on a central pole orshaft comprising split collar means, means for detachably fastening saidsplit collar means together and about said central pole or shaft, aplurality of horizontal struts extending radially from said collarmeans, each said horizontal strut being pivotally mounted on said collarmeans and comprising back to back channel members, each said channelmember having a base, parallel sides extending from said base, andreentrant flanges extending inwardly from each said side and defining achannel opening, a plurality of vertical struts, equal in number to thenumber of horizontal struts, pivotally connected to the outer ends ofsaid horizontal struts, respectively, and pivotally connected to saidcollar means in vertically spaced relation with said pivotal connectionsof said horizontal struts with said collar means, and a plurality ofplatform members, equal in number to the number of said horizontalstruts, each said platform member having lateral edges and extendingbetween a pair of adjacent horizontal struts with said lateral edgesbearing upon the respective adjacent reentrant flanges thereof, a flangeon each edge of each said platform member and disposed in the adjacentsaid channel opening of the adjacent said horizontal strut, and cleatsmounted on the under side of each said platform member and disposedinteriorly of the adjacent edge of said platform member and the adjacentsaid horizontal strut.

2. The scaffolding according to claim 1 in which said vertical strutscomprise an inner rod member and an outer tubular member in telescopicrelation therewith and said vertical strut members are movable andextensible relative to each other.

3. The scaffolding according to claim 1 in which said collar meanscomprises upper and lower, vertically spaced collars, each said collarcomprises two halves, rigid connector means interconnect each half of asaid collar with the corresponding half of the other said collar, saidhorizontal struts are pivotally connected to said upper collar, and saidvertical struts are pivotally connected to said lower collar.

4. The scaffolding according to claim 1 in which said collar meanscomprises upper and lower, vertically spaced collars, said horizontalstruts are pivotally connected to said upper collar, and said verticalstruts are pivotally connected to said lower collar.

5. The scaffolding according to claim 4 in which each said collarcomprises two halves, said collar halves have edges forming meetinglines, gudgeons at each edge of each said collar half, said gudgeonsinterlocking with the gudgeons of the opposite collar half to receive apin for connecting said collar halves together, said gudgeons on acollar half being complementary to each other, whereby said collarhalves are similar and interchangeable with respect to said gudgeons.

6. The scaffolding according to claim 5 in which said struts arepivotally connected to said collars on lug means, and said lug means areequiangularly spaced about said collars and symmetrically spacedrelative to said edges of each said collar half, whereby said collarhalves are similar and interchangeable.

7. The scaffolding according to claim 1 in which said struts areequiangularly spaced about said collar means.

8. The scaffolding according to claim 1 in which each of said platformmembers comprise a plurality of sections hinged together on linesextending transversely of said edges.

9. A folding collapsible scalfolding for mounting on a central pole orshaft comprising collar means, means for detachably fastening saidcollar means about said central pole or shaft, a plurality of horizontalstrut means extending radially from and pivotally connected to saidcollar means, a plurality of vertical strut means, equal in number tothe number of horizontal strut means, pivotally connected to the outerends of said'horizontal strut means, respectively, and pivotallyconnected to said collar means in vertically spaced relation with saidconnections of said horizontal strut means with said collar means, andplatform means extending between and supported on adjacent horizontalstrut means, respectively.

16. The scaffolding according to claim 9 in combination with a vesselhaving an agitator shaft in which said agitator shaft comprises saidcentral shaft or pole.

11. The scaffolding according to claim 9 in which said vertical strutmeans comprise inner and outer telescopically related members one ofwhich is connected to a horizontal strut means and the other of which isconnected to said collar means.

12. The folding collapsible scaffolding according to claim 9 in whichsaid platform means comprises a plurality of platforms, equal in numberto the number of horizontal strut means, and each said platform extendsbetween a pair of adjacent horizontal strut means and has lateral edgessupported on said adjacent horizontal strut means, respectively.

13. The scaffolding according to claim 12 in which each said platformcomprises a plurality of sections hinged together on lines extendingtransversely of said edges.

14. The scaffolding according to claim 12 with means preventing lateraldisplacement of said platforms relative to said strut meansrespectively.

15. The scaffolding according to claim 14 in which said last named meanscomprises upwardly opening channel means in each said horizontal strutmeans and flange means at each end of each said platform and disposed inthe adjacent said channel means.

16. The scaifolding according to claim 9 in which said collar meanscomprises upper and lower, vertically spaced collars, said horizontalstrut means are pivotally connected to said upper collar, and saidvertical strut means are pivotally connected to said lower collar.

17. The scaffolding according to claim 16 in which each said collarcomprises two halves, and rigid connector means interconnect each halfof a said collar with the corresponding half of the other said collar.

References Cited by the Examiner UNITED STATES PATENTS 1,071,177 8/1913Reichert 182-128 X 1,197,999 9/1916 Beckett 182-187 1,231,823 7/1917Weasler 182187 X 1,251,066 12/1917 McClanahan 182-428 X FOREIGN PATENTS594,501 6/ 1959 Italy.

REINALDO P. MACHADO, Primary Examiner.

9. A FOLDING COLLAPSIBLE SCAFFOLDING FOR MOUTING ON A CENTRAL POLE ORSHAFT COMPRISING COLLAR MEANS, MEANS FOR DETACHABLY FASTENING SAIDCOLLAR MEANS ABOUT SAID CENTRAL POLE OR SHAFT, A PLURALITY OF HORIZONTALSTRUT MEANS EXTENDING RADIALLY FROM AND PIVOTALLY CONNECTED TO SAIDCOLLAR MEANS, A PLURALITY OF VERTICAL STRUT MEANS, EQUAL IN NUMBER TOTHE NUMBER OF HORIZONTAL STRUT MEANS, PIVOTALLY CONNECTED TO THE OUTERENDS OF SAID HORIZONTAL STRUT MEANS, RESPECTIVELY, AND PIVOTALLYCONNECTED TO SAID COLLAR MEANS IN VERTICALLY SPACED RELATION WITH SAIDCONNECTIONS OF SAID HORIZONTAL STRUT MEANS WITH SAID COLLAR MEANS, ANDPLATFORM MEANS EXTENDING BETWEEN AND SUPPORTED ON ADJACENT HORIZONTALSTRUT MEANS, RESPECTIVELY.